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sidebar_position: 1
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# Installation

## Supported Environments

LangChain is written in TypeScript and can be used in:

- Node.js (ESM and CommonJS) - 18.x, 19.x, 20.x
- Cloudflare Workers
- Vercel / Next.js (Browser, Serverless and Edge functions)
- Supabase Edge Functions
- Browser
- Deno
- Bun

However, note that individual integrations may not be supported in all environments.

## Installation

To get started, install LangChain with the following command:

import Tabs from "@theme/Tabs";
import TabItem from "@theme/TabItem";
import CodeBlock from "@theme/CodeBlock";

<Tabs>
  <TabItem value="npm" label="npm" default>
    <CodeBlock language="bash">npm install -S langchain</CodeBlock>
  </TabItem>
  <TabItem value="yarn" label="Yarn">
    <CodeBlock language="bash">yarn add langchain</CodeBlock>
  </TabItem>
  <TabItem value="pnpm" label="pnpm">
    <CodeBlock language="bash">pnpm add langchain</CodeBlock>
  </TabItem>
</Tabs>

### TypeScript

LangChain is written in TypeScript and provides type definitions for all of its public APIs.

## Installing integration packages

LangChain supports packages that contain specific module integrations with third-party providers.
They can be as specific as [`@langchain/google-genai`](/docs/integrations/platforms/google#chatgooglegenerativeai), which contains integrations just for Google AI Studio models,

These packages, as well as the main LangChain package, all depend on [`@langchain/core`](https://www.npmjs.com/package/@langchain/core), which contains the base abstractions
that these integration packages extend.

To ensure that all integrations and their types interact with each other properly, it is important that they all use the same version of `@langchain/core`.
The best way to guarantee this is to add a `"resolutions"` or `"overrides"` field like the following in your project's `package.json`. The name will depend on your package manager:

If you are using `yarn`:

```json title="yarn package.json"
{
  "name": "your-project",
  "version": "0.0.0",
  "private": true,
  "engines": {
    "node": ">=18"
  },
  "dependencies": {
    "@langchain/google-genai": "^0.0.2",
    "@langchain/core": "^0.3.0"
  },
  "resolutions": {
    "@langchain/core": "0.3.0"
  }
}
```

Or for `npm`:

```json title="npm package.json"
{
  "name": "your-project",
  "version": "0.0.0",
  "private": true,
  "engines": {
    "node": ">=18"
  },
  "dependencies": {
    "@langchain/google-genai": "^0.0.2",
    "@langchain/core": "^0.3.0"
  },
  "overrides": {
    "@langchain/core": "0.3.0"
  }
}
```

Or for `pnpm`:

```json title="pnpm package.json"
{
  "name": "your-project",
  "version": "0.0.0",
  "private": true,
  "engines": {
    "node": ">=18"
  },
  "dependencies": {
    "@langchain/google-genai": "^0.0.2",
    "langchain": "0.0.207"
    "@langchain/core": "^0.3.0"
  "pnpm": {
    "overrides": {
      "@langchain/core": "0.3.0"
    }
  }
}
```

### @langchain/community

The [@langchain/community](https://www.npmjs.com/package/@langchain/community) package contains third-party integrations.
It is automatically installed along with `langchain`, but can also be used separately with just `@langchain/core`. Install with:

```bash npm2yarn
npm install @langchain/community @langchain/core
```

### @langchain/core

The [@langchain/core](https://www.npmjs.com/package/@langchain/core) package contains base abstractions that the rest of the LangChain ecosystem uses, along with the LangChain Expression Language.
It is automatically installed along with `langchain`, but can also be used separately. Install with:

```bash npm2yarn
npm install @langchain/core
```

import IntegrationInstallTooltip from "@mdx_components/integration_install_tooltip.mdx";

<IntegrationInstallTooltip></IntegrationInstallTooltip>

## Loading the library

### ESM

LangChain provides an ESM build targeting Node.js environments. You can import it using the following syntax:

```bash npm2yarn
npm install @langchain/openai @langchain/core
```

```typescript
import { ChatOpenAI } from "@langchain/openai";
```

If you are using TypeScript in an ESM project we suggest updating your `tsconfig.json` to include the following:

```json title="tsconfig.json"
{
  "compilerOptions": {
    ...
    "target": "ES2020", // or higher
    "module": "nodenext",
  }
}
```

### CommonJS

LangChain provides a CommonJS build targeting Node.js environments. You can import it using the following syntax:

```typescript
const { ChatOpenAI } = require("@langchain/openai");
```

### Cloudflare Workers

LangChain can be used in Cloudflare Workers. You can import it using the following syntax:

```typescript
import { ChatOpenAI } from "@langchain/openai";
```

### Vercel / Next.js

LangChain can be used in Vercel / Next.js. We support using LangChain in frontend components, in Serverless functions and in Edge functions. You can import it using the following syntax:

```typescript
import { ChatOpenAI } from "@langchain/openai";
```

### Deno / Supabase Edge Functions

LangChain can be used in Deno / Supabase Edge Functions. You can import it using the following syntax:

```typescript
import { ChatOpenAI } from "https://esm.sh/@langchain/openai";
```

or

```typescript
import { ChatOpenAI } from "npm:@langchain/openai";
```

We recommend looking at our [Supabase Template](https://github.com/langchain-ai/langchain-template-supabase) for an example of how to use LangChain in Supabase Edge Functions.

### Browser

LangChain can be used in the browser. In our CI we test bundling LangChain with Webpack and Vite, but other bundlers should work too. You can import it using the following syntax:

```typescript
import { ChatOpenAI } from "@langchain/openai";
```

## Unsupported: Node.js 16

We do not support Node.js 16, but if you still want to run LangChain on Node.js 16, you will need to follow the instructions in this section. We do not guarantee that these instructions will continue to work in the future.

You will have to make `fetch` available globally, either:

- run your application with `NODE_OPTIONS='--experimental-fetch' node ...`, or
- install `node-fetch` and follow the instructions [here](https://github.com/node-fetch/node-fetch#providing-global-access)

You'll also need to [polyfill `ReadableStream`](https://www.npmjs.com/package/web-streams-polyfill) by installing:

```bash npm2yarn
npm i web-streams-polyfill@4
```

And then adding it to the global namespace in your main entrypoint:

```typescript
import "web-streams-polyfill/polyfill";
```

Additionally you'll have to polyfill `structuredClone`, eg. by installing `core-js` and following the instructions [here](https://github.com/zloirock/core-js).

If you are running Node.js 18+, you do not need to do anything.
